Counting and stacking apparatus



Aug. 25', 1970 J. B. POMARA, JR coun'rme AND STACKING APPARATUS sSheets-Sheet 1 Filed June 10. 1968 INVENTOR. Johnny B. Pomaru,Jr. BY+.W$=M

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Aug. 25, 1970 J. B. POMARA, JR

COUNTING AND STACKING AYPARATUS 3 Sheets-Sheet 2 Filed June 10, 1968 mumFig.5

INVENTOR. Johnny B. Pamoro,Jr. BY

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Johnny B1.Pq moro,Jr.

BY wmkm ATTORNEY United States Patent Office 3,525,443 Patented Aug. 25,1970 3,525,443 COUNTING AND STACKIN G APPARATUS Johnny B. Pomara, Jr.,Dallas, Tex., assignor of fifty percent to El Chico Corporation, Dallas,Tex., a corporation of Texas Continuation-impart of application Ser. No.657,244, July 31, 1967. This application June 10, 1968, Ser. No.

Int. Cl. B65g 57/06 US. Cl. 214-6 4 Claims ABSTRACT OF THE DISCLOSUREApparatus for counting and stacking substantially flat articlesincluding a stacking conveyor, a stacking plate, a stacking guide, stacksupport and discharge plates, and a discharge conveyor. The stackingconveyor deposits each article on the stacking plate which immediatelyretracts dropping the article downwardly to the support and dischargeplates which retract when a desired predetermined number of articles arestacked dropping the stack to the discharge conveyor.

This application is a continuation-in-part of an application entitledCounting and Stacking Apparatus filed by Johnny B. Pomara, Jr. on July31, 1967, Ser. No. 657,244.

This invention relates to counting and stacking apparatus andparticularly a system for counting and stacking substantially flatarticles.

It is an object of the invention to provide new and improved apparatusfor use in a packaging system for counting and stacking in verticallyaligned relationship a predetermined number of substantially flatarticles and discharging each stack toward a packaging station forplacement in containers. The apparatus is especially adapted to countingand stacking of food products such as tortillas.

It is another object of the invention to provide apparatus of thecharacter described wherein each stack of articles handled by theapparatus contains a predetermined number of such articles which numberis variable by adjustment of counting and control means included in theapparatus.

It is still another object of the invention to provide apparatus of thecharacter described which is especially adapted to handling soft,flexible, substantially flat articles with a minimum of folding andwrinkling.

It is another object of the invention to provide apparatus of thecharacter described which includes stack supporting and discharge platemeans movable between stack supporting and stack discharging positions.

It is a further object of the invention to provide counting and stackingapparatus of the character described including stacking plate meanswhich momentarily supports and guides each stacked article betweenstacking conveyor and stack support and discharge plates below thestacking plate.

It is a still further object of the invention to provide apparatus ofthe character described which in its preferred form includes a stackingconveyor, stacking plate for receiving each article to be stacked fromthe stacking conveyor and momentarily supporting and discharging thearticle downwardly responsive to engagement of a trigger-like lever byeach article as it moves to the stacking plate, a stacking guide forguiding and holding a stack of such articles in vertical alignedrelationship, stack support and discharge plates means below thestacking guide and movable between stack supporting and stackdischarging positions, for supporting the articles in stacked array, anda discharge conveyor for receiving each stack of articles for movementto a packaging station.

Additional objects and advantages of the invention will be readilyapparent from reading the following description of apparatus constructedin accordance with the invention and by reference to the accompanyingdrawings thereof, wherein:

FIG. 1 is a side view in elevation of counting and stacking apparatusembodying the invention showing the stacking and the stack support anddischarge plates at closed positions;

FIG. 2 is a top plan view of the apparatus of FIG. 1;

FIG. 3 is a top plan view of a portion of the apparatus of FIG. 1 asviewed from a plane generally along the line 3-3 of FIG. 1 illustratingthe stack support and discharge plates at closed positions;

FIG. 4 is an enlarged fragmentary side view of a portion of theapparatus showing the stacking plate open or retracted for dropping asingle article to the stack support and discharge plates which are atclosed stack supporting positions;

FIG. 5 is a fragmentary side view partially in section, similar to FIG.4, showing the stack support and discharge plates retracted or open forreleasing a stack downwardly to the discharge conveyor and the stackingplate partially returned toward its closed position;

FIG. 6 is an enlarged fragmentary top view of the apparatus showingparticularly the air spray system and the stacking plate at its closedposition; and

FIG. 7 is a schematic circuit diagram of the electrical and air controland operating systems of the counting and stacking apparatus.

Referring to the drawings, a counting and stacking system 20'constructed in accordance with the invention includes a stackingconveyor 21, a stacking guide 22, a stacking plate 23, and stack supportand discharge plates 24 and 25. A cooling conveyor 30 and a dischargeconveyor 31 are shown for moving units to be counted and stacked to thesystem and for removing each stack of counted units from the system to aremote location, such as a packaging station, not shown. Units beinghandled by the apparatus, such as the circular units 32, are fed intothe system on the cooling conveyor 30 at the upper end of which eachunit is deposited on a line-up slide 33 which guides them to anddeposits them on the stacking conveyor 21. The conveyor 21 propels eachunit onto the top face of the stacking plate which retracts to drop eachunit downwardly in the stacking guide 22 to the stack support anddischarge plates 24 and 25. When the desired predetermined number ofunits has been deposited and stacked in aligned relationship on theplates 24 and 25 the plates are rapidly retracted or opened away fromeach other dropping a stack 32a of the units to the discharge conveyor31 which moves the stack in the direction of the arrow 34 away from thecounting and stacking system toward additional process apparatus such asa packaging station, not shown. The counting and stacking system,particularly when handling tortillas, is generally located between ovensin which the tortillas are cooked and a packaging station at which theyare placed in containers for shipment.

The cooling conveyor 30 is a suitable conventional conveyor having legs35 and 40 of suitable length to provide the desired height and slope tothe conveyor. The legs 35 and 40 are provided with adjustable footmembers 35a and 40a respectively, to permit minor height and attitudeadjustments to the conveyor. The supporting structure for the endlessflexible belt 41 of the conveyor 30 includes side beams 42 which holdsuitable belt supporting rollers 43 mounted on end bearings 44. The beltis driven by suitable conventional power means, not shown.

The discharge conveyor 31 is also a conventional conveyor including aflexible endless belt 45, supported on spaced end rollers 50 and 51which are mounted between parallel, spaced, side beams 52. The roller 50is supported on bearings 53 which are each movable in an H-frame 54 byadjustment of a screw 55 to maintain the proper tension in the conveyorbelt. The roller 51 is supported on bearings 60 and is connected at oneend with a gear 62 driven by a chain 63 extending to a prime mover, suchas an electric motor, not shown, for operating the conveyor. Thedischarge conveyor is mounted on spaced legs 64 secured along theirupper ends to the beams 52 and supported at their lower ends onadjustable foot members 65. The legs 64 are connected and braced byhorizontally extending lower side members 70 which also support portionsof the controls for the system as explained in detail below. Upperhorizontal side braces 71 extend between the legs 64 and the legs 40 ofthe conveyor 30.

The line-up slide 33 which guides each item from the conveyor 30 to thestacking conveyor 32 includes a main panel or bottom 80 providing a topsliding surface 81 between side upturned flange or edge portions 82which aid in guiding the items down the slide and prevent sliding ofl?the slide laterally. The slide is slightly wider at the top end than atthe bottom end to permit some tolerance in the positioning of the itemson the conveyor 30 so that if they are displaced laterally on theconveyor to one side or the other of the center of the slide, they stillgenerally will be fed into the slide at its upper end. The more narrowlower end of the slide, however, causes each item to be properlycentrally positioned along the centerline of the stacking conveyor. Thetop surface of the slide preferably is coated with a suitable materialsuch as a plastic sold under the trademark Teflon to enhance the slidingcharacteristics of the surface so that each item properly acceleratesdown the slide and does not tend to stick on the surface of the slide.The slide is supported on frame members 83 which are mounted on the endsof side plates 82 of the stacking conveyor 21.

The stacking conveyor 21 has an endless flexible belt 85 movablysupported on spaced end rollers 90 and 91 which are mounted on bearings90a and 910, respectively, secured to the side plates 84 of theconveyor. The side plates are suitably supported from integral brackets92 and 93 which extend to and are connected with the side plates 52 ofthe discharge conveyor. The conveyor belt 85 comprises a suitableflexible wire mesh material which provides maximum cooling of food itemsas they move from the slide toward the stacking plate and guide.

The stacking guide 22 is a U-shaped member having leg portions extendingtoward the stacking conveyor and secured along inwardly turned leg-endflanges 100, FIG. 6, to a cross member 101 extending between the sideplates 84 of the stacking conveyor. The stacking guide defines avertical opening or passage 22a slightly larger than the items beingstacked in it. Each item passes into the upper end of the opening fromthe stacking conveyor and is confined in the opening in stacked array onthe plates 24 and 25 until released by opening the plates apart. Thestacking guide has a horizontal slot 102 opening toward the stackingplate 23 and positioned and of suflicient height to freely receive thehorizontally moving stacking plate to permit the plate to move betweenthe closed positions of FIGS. 1, 2, and 6 and the open position of FIG.4. Guide blocks 103 and 104 are mounted in spaced relationship along theoutside surface of the bight of the U-shaped stacking guide above andbelow the slot 103 to guide the stacking plate back into the slot as itmoves from its maximum open position of FIG. 4 back toward its closedposition as in FIG. 5. The guide blocks minimize the possibility of thestacking plate becoming misaligned from the mouth of the slot when atits maximum open or retracted position due to possible verticaldeflection which in the absence of the guide blocks might cause theplate to miss the slot and jam against the outer surface of the stackingguide. The guide blocks thus allow complete withdrawal of the stackingplate from the opening 22a through the stacking guide. Similarly theguide blocks 105 and are secured adjacent to the lower edge of thestacking guide to prevent jamming of either of the plates 24 and 25against the stacking guide in the event of upward deflection of theplates and thus allow complete withdrawal of the plates from below thelower open end of the stacking guide so that a stack 32a of items in theguide on the plates 24 and 25 may drop downwardly without interferencefrom either of the plates. The stacking guide insures substantialvertical alignment of the stacked items on the stack support anddischarge plates.

The stacking plate 23 is mounted on the end of a piston rod connectedwith a piston 120a in a double acting air cylinder 121 for supportingand moving the stacking plate between its open and closed positions. Theair cylinder is secured through a fitting 122 at one end connected on anL-shaped bracket 123 having an up turned end portion 124 secured withthe end of the cylinder near the stacking plate to provide verticalsupport and stability to the cylinder. The bracket 123 is supported on amount 124 which spans the discharge conveyor and has vertical legs 125extending dowwardly and connected with the side plates 52 of thedischarge conveyor. The piston rod 120 of the air cylinder 121 isextended and retracted for closing and opening the stacking plate 23, orfor moving the stacking plate between its stacking and releasepositions, responsive to air pressure supplied to opposite ends of thecylinder by lines and 131 which are connected with an electricallyoperated air valve 132 communicating through a line 132a with a tank 133from which air under pressure is selectively supplied through the valvefor extending and retracting the air cylinder piston rod.

The movement of the stacking plate 23 is controlled by a hair-like leveror feeler 134 supported from and actuating a micro-switch 135 whichsimultaneously controls operation of the air cylinder 121 and an airhead which supplies jets of air downwardly against each item on thestacking plate 23 as the plate is retracted so that the item is forcedrapidly and evenly downwardly to its stacked relationship on the plates24 and 25. The microswitch and air head are both supported over the openupper end of the stacking guide 22 from a cross angle bar 141 secured atopposite ends to the side plates 84 of the stacking conveyor. Themicro-switch is connected to the vertical side surface of a bracket 142which is suitably secured as by welding at one end to the cross bar 141.The air head is supported from the bracket 142 by a clamp 143 secured tothe bracket and to a supporting supply line 144 connected with the airhead. The air head includes a cross connection 145 secured to identicalvalves each of which supplies, supports, and controls air flow to adownwardly projecting jet tube or nozzle 151. The three nozzles used inthis particular form of air head are spaced to distribute downwardlyflowing air from the nozzles over the top surface area of the itemshandled by the apparatus so that there is a substantial balance of airpressure against each item forcing each item downwardly from thestacking plate when it is rapidly withdrawn responsive to the movementof the lever 134 on the micro-switch.

The air supply line 144 leading to the air head 140 is connected throughan electrically operated air valve 152 into the air tank 133. The lever134 on the microswitch extends downwardly to a substantial depth withinthe stacking guide 22 to insure that when an item to be stacked islaunched from the stacking conveyor into the stacking guide the lever iscontacted by the item. An elongate slot 23a, FIG. 6, is provided in thestacking plate 23 opening toward the lever 134 and positioned in theplate to receive the lever as the plate moves toward and away from itsclosed position. As shown in FIGS. 1 and 5 the lower end of the leverextends somewhat below the stacking plate. The slot 23a is of sufiicientwidth and length to preclude any interference between the lever and theplate so that any normal flexing of the lever during operating of theapparatus either by way of vibration or by engagement by the items beingstacked, will not cause the lever to jam or otherwise interfere with thestacking plate. The stacking plate freely moves over and is retractedfrom the lever during its horizontal movements between its fully closedposition shown in FIGS. 1 and 6 and its fully retracted position of FIG.4. The lever 134 is flexible and somewhat fragile so that it is easilydeflected upwardly by an item, such as a tortilla, projected downwardlyand outwardly against its lower surface from the stacking conveyor.

The stack support and discharge plates 24 and 25 are operably supportedfrom identical double acting air cylinders 160 and 161, respectively,for moving the stacking plates between stack supporting and stackdischarging positions. The cylinder 160 supports the stacking plate 24on a piston rod 162 connected with a piston 163 which is displacedbetween end positions by air under pressure selectively supplied toopposite ends of the cylinder through lines 164 and 165, respectively,which are connected with an electrically operated control valve 170 forsupplying air from the air tank 133 to the air cylinder to move theplate 24 in both opening and closing directions. The air cylinder 160 issecured by bracket 166 on a cross member 167 which spans the dischargeconveyor belt and has vertical leg portions 168 secured to the sidebeams 52 of the discharge conveyor. Similarly, the stacking plate 25 issupported on piston rod 171 of the air cylinder 161. A piston 172connected with the piston rod 171 is similarly displaced in oppositedirections by air selectively supplied from the valve 170 to the aircylinder 161 through lines 173 and 174 connected between the valve andthe air cylinder. The air cylinder 161 is secured on a bracket 175mounted on a lateral support 180 also spanning the discharge conveyorbelt and having leg end portions 181 connected with the side beams 52 ofthe discharge conveyor.

The stacking plates 24 and 25 with their related air cylinder units arepositioned such that the adjacent end edges of the plates are closelyspaced from each other when the plates are at closed stack supportingpositions as shown in FIG. 4 so that a stack on the plates issubstantially equally supported by both of the plates. The stroke ofeach of the air cylinder pistons is of a length to retract each of theplates to an open position at which the adjacent end edges of the platesare clear of the lower open end of the stacking guide 22 to allow astack to be freely discharged downwardly from the guide as evident inFIG. 5. The plates 24 and 25 are substantially in the same plane andremain in such plane during their horizontal movement between open andclosed positions. The plates are retracted so rapidly that a stacksupported on them is released to drop in a horizontal position to thedischarge conveyor belt.

A counting switch 224 is supported from a bracket 225 secured with thebracket 123 below the stacking plate 23. The counting switch has a lever230 engageable by the stacking plate 23 each time the plate retracts fordropping an item downwardly as illustrated in FIG. 4. When the stackingplate is returned to its fully closed position as in FIGS. 1 and 6 thecounting switch is released by the stacking plate. The counting switchis interconnected with a counter unit 273 and a time delay relay 274 foroperation of the stacking and discharge plates when a desiredpredetermined number of items have been stacked on the plate.

The electrical and air systems circuitry for controlling the operationof the counting and stacking apparatus are illustrated schematically inFIG. 7. For purposes of clarity the electrical conductors of FIG. 7 arenot all shown in all of the other figures of the drawings. It is to beunderstood, however, that electrical conductors and air lines as shownin FIG. 7 are interconnected between the various electrical and aircomponents of the apparatus for supplying air under pressure to thevarious air cylinders and properly timing the operations of thecylinders. The circuitry controls the movement of the stacking plate 23,the air flow from the air head 140, and the opening and closing of thestack support and discharge plates 24 and 25 in accordance with adesired program for which the adjustable control components of thesystem are set. One suitable counter 273 is a Cycle-Flex counter, seriesHZl, manufactured by Bliss-Eagle Signal, a division of E. W. BlissCompany, Davenport, Iowa. The time delay relay 274 may be a model10337Hl92A, 60 cycle, made by Cutler-Hammer, Inc.

The counter 273 includes a counting assembly 280 having a stepping motorwhich advances one step each time it is deeuergized. The stepping motoris mechanically coupled with a solenoid actuated clutch 281 having asolenoid coil 281a which, when energized as described below, causes thecounting assembly to reset to zero preparatory to starting the nextcounting cycle. The counting assembly is coupled with a switch 282included in the counter which when closed connects the counting switch224 in a circuit with the counting assembly 280. The counting assemblyis also coupled with a switch 283 included in the counter whichenergizes the time delay relay 274. The time delay relay includes asolenoid coil 284 which when energized causes its contacts 285 and 290to close to energize both the solenoid 281a of the clutch 281 of thecounter and a solenoid coil 271a of the air valve 170. The time delayrelay includes a bellows, not shown, having an air bleed hole whichallows air to be drawn into and expelled from the bellows at anadjustable rate to control the expansion and contraction of the bellowswhich is moved in one direction by the coil 284 when energized. The coil284 moves the bellows and closes the contacts 285 and 290 with the rateof air flow through the bleed hole in the bellows con trolling thereturn rate of movement of the bellows in the opposite direction foropening the contacts 285 and 290 after a predetermined time delaycontrolled by the bellows. The counter 273, the time delay relay 274,and the air valve 170 are connected with main line conductors 291 and292 extending to a suitable volt, 60 cycle, power supply 292a, asexplained in more detail below.

One side of the counting switch 224 is connected to the main lineconductor 292 by a conductor 293. The other side of the counting switchis connected by a conductor 294 to one side of the switch 282 in thecounter unit 273. The other side of the switch 282 is connected by aconductor 295 to one side of the motor of the counting assembly 280'theother side of which is connected by conductors 300 and 301 to the othermain line conductor 291. One side of the clutch solenoid 281a isconnected by the conductor 291 to the conductor 30.1 and the other sideof the clutch solenoid is connected by a conductor 302 to one side ofthe contact 285 of the time delay relay 274. The other side of thiscontact 285 is connected by a conductor 303 to the main line 292. Thetime delay relay winding 284 is connectable across the main lineconductors by way of the conductor 304, the switch 283 of the counterand the conductors 305 and 310. When energized the winding 284 causesboth the contacts 285 and 290 to move to close position.

The solenoid 271a of the air valve 170 is connected on one side with themain line conductor 292 through the conductor 311, the contact 290, andthe conductor 312. The other side of the solenoid 271a is connected withthe main line conductor 291 by the conductor 313 so that closure of thecontact 290 energizes the solenoid.

The micro-switch 135 which controls the operation of the stacking plate23 and the air head 140 is connected on one side to the main lineconductor 291 and on the other side to conductors 314 and 314 leading tothe solenoid coil 132a of the air valve 132 for the stacking plate andthe solenoid 152a of the air valve 152 for the air head 140,respectively. The other sides of the solenoid coils 132a and 152a areconnected with the main line conductor 292 by conductors 320 and 321,respectively, so that when the switch 135 is closed by the lever 134 thesolenoids for both the air valve for the stacking plate and the air headover the stacking plate are energized.

The air valve 132 has a movable valve member 132k provided with an airsupply passage network .1320 which connects the air supply tank 133 withthe air line 130 at one end position of the valve member and connectsthe air supply tank with the other air line 131 at the other endposition of the valve member. The valve member has exhaust passages 132dand 132a which selectively communicate with the air lines 130 and 131,respectively, and corresponding exhaust ports in the air valve cylinderfor exhausting one end of the air cylinder 121 while air under pressureis supplied through the valve 132 to the other end of the cylinder. Forexample, in the position illustrated in FIG. 7 the end of the aircylinder 121 nearest the stacking plate 23 is exhausted through the line131 and the exhaust passage 1322 while air under pressure is supplied tothe other end of the air cylinder from the supply tank through the flowpassage network 1320 and the air line 130 for holding the stacking plate23 at its closed position at which the piston rod 120 is fully extended.The piston rod is retracted and the stacking plate moved to its openposition by shifting the valve member 132b to its other end position atwhich air under pressure is supplied to the line 131 through the airflow network 1320 while air is exhausted from the air cylinder 121through the air line .130 and the exhaust flow passage 132d in the valvemember.

Air is supplied to the stacking and discharge plate air cylinders 160and 161 through the air valve 170 which has a movable valve member 170ahaving an air supply passage network 17% and exhaust passages 1700 and17011. Air is supplied to the far or outward ends of the air cylinders160 and .161 through the air lines 164 and 174 which connect with a line166 leading to the valve 170 so that when the valve member 170a is inthe position shown in FIG. 7 air is supplied from the air tank 133through the flow passage network 17% to the line 166 and connectinglines 164 and 174 to the far ends of the air cylinders 160 and 161forcing the pistons 163 and 172 toward each other and holding thestacking plates 24 and 25 at their closed adjacent positions. At thisposition of the air valve member the near or inward ends of the aircylinders 160 and 161 are vented to the atmosphere through the air lines165 and 173 which connect with a line 167 to the air valve which ventsthe line 167 to the atmosphere through the passage 1700! of the valvemember 170a. When the air valve member 170a is shifted by its solenoidcoil 271a to its other end position the supply tank is communicatedthrough the flow passage network 17% with the line 167 and theconnecting lines 165 and 173 applying air under pressure into the nearends of the air cylinders 160 and 161 and venting the outward ends ofthe air cylinders to the atmosphere through the line 164, 174, and .166,and through the air valve member exhaust passage 1700. At this positionof the air valve the pistons 163 and 172 are moved apart therebyretracting the piston rods 162 and 171 shifting the plates 24 and 25apart to their open positions.

The air head 140 communicates with the air supply tank 133 through theline 144 and the air valve 152 which has a valve member 1521) movable bythe solenoid 152a. The valve member has an air supply passage 152a forcommunicating the air tank with the line 144 at one position of thevalve member and a vent passage 152d which vents the air head system atthe other position of the valve member, as shown in FIG. 7.

The various switches, contacts, air valves, and the like are normallypositioned as illustrated in FIG. 7. The clutch 281 of the counter 273and the time delay relay 274 are not activated and the solenoids of theair valves 132 and 170 are all deenergized since the switch 283 is open.With the switch 283 open, the relay winding 284 is not energized so thatthe contacts 285 and 290 of the time delay relay are at open positions.With the contacts 285 and 290 open no power is supplied to the solenoid281a of the counter and the solenoid of the air valve 170. With the airvalve solenoid 271a deenergized its valve member 170a is positioned asshown in FIG. 7 so that the air pressure in the opposite ends of thepistons 1'60 and 161 maintain the plates 24 and 25 at their closed,stack receiving positions. Similarly, with the switch 135 open thesolenoids 132a and 152a of the air valves 132 and 152, respectively, aredeenergized and their valve memhers are positioned as illustrated sothat the stacking plate 23 is held at its closed position and no air issupplied through the air valve 152 to the air head 140 above thestacking plate.

As each article processed by the apparatus is launched from the stackingconveyor belt into the stacking guide 22 onto the stacking plate, themicro-switch lever 134 is contacted by the item and raised therebyclosing the micro-switch 135 energizing the solenoid 132a of the airvalve 132 for the stacking plate 23 and the solenoid 152a of the airvalve 152 for the air head 140. The air valve member 132a is shifted toits other end position supplying air to the air cylinder 121 through theline 131 moving the stacking plate from the closed position of FIGS. 1and 2 to the open position of FIG. 4. Simultaneously with the opening ofthe stacking plate the solenoid of the air valve 152 shifts the valvemember 152b to supply air through the nozzles 151 providing a highvelocity air blast downwardly against the top face of the item on thestacking plate so that as the stacking plate is rapidly retracted orwithdrawn from beneath the item the air blast forces the item downwardlyincreasing its velocity over the normal falling rate of the item afterthe stacking plate is withdrawn from beneath it. The item dropsdownwardly within the stacking guide 22 to the stack support anddischarge plates 24 and 25. As the stacking plate 23 is retracted to theposition of FIG. 4 the lower surface of the plate engages the lever 230on the counting switch 224 closing the switch and energizing the motorof the counting assembly 280 so that when the counting switch isreleased by return of the stacking plate to its closed position openingthe circuit through the counting switch and the assembly 280, thecounting device advances one step.

As the item drops downwardly to the stack support and discharge plates,the lever 134 returns downwardly opening the micro-switch 135deenergizing the solenoids 132a and 152a and returning the valve memberof the air valve 132 to its normal position to supply air to thecylinder 121 through the line moving the stacking plate back to itsnormal closed position in the stacking guide. The deenergizing of thesolenoid 152a returns the air valve 152 to the position shown in FIG. 7shutting off the downward air flow from the nozzles 151. As the stackingplate 23 returns to its closed position the counting switch lever 230 onthe micro-switch 224 is released opening the switch and the circuitthrough the switch and the assembly 280 so that the counting device inthe counter 27 3 advances one step.

The supplying of the items to be counted and stacked on the stackingconveyor continues with each item being dropped downwardly one at a timeby the retraction of the stacking plate 23 until the desired number ofitems for which the counter is set has been deposited by the stackingplate on the stack support and discharge plates 24 and 25. At that timethe counting assembly 280 moves the switch 282 to its open position andmomentarily closes the switch 283 connecting the relay winding 284across the main line conductors. This momentary energizing of thewinding 284 closes the contacts 285 and 290 connecting the solenoid 281aof the clutch 281 and the solenoid 271a of the air valve 170 across themain line. Energizing the solenoid 271a shifts the air valve 170 to itsother end position for supplying air to the inward or near ends of theair cylinders 160 and 161 thereby closing the air cylinders and movingthe stack support and discharge plates 24 and 25 apart from each otherto their open positions dropping the stack downwardly from the stackingguide to the discharge conveyor below the stacking guide and plates.FIG. 5 illustrates the position of the stack support and dischargeplates at their fully opened positions for releasing a stack downwardlyfrom the plates. Since the stacking plate 23 operates responsive to thelever 134 and independently of the counter, the plate 23 returns toclosed position after dropping each item; and thus when the plates 24and 25 are open to drop a counted stack, the plate 23 generally will bealready returning to closed position as in FIG. 5.

The air cylinders remain closed with the stacking plates open so long asthe solenoid coil 271a of the air valve 170 is energized. The closing ofthe switch 283 only momentarily energizes the relay winding 284 which isthen immediately deenergized. The contacts 285 and 290, however, areheld at their closed positions by the bellows of the relay with the rateof air flow through the bellows controlling the opening of the contacts.The time delay relay 274 is adjusted to hold the contacts 289 and 290closed for a sufficient length of time for the complete stack of itemsto drop downwardly from the open stack support plates to the dischargeconveyor below. The closed contact 285 maintains the solenoid 281a ofthe clutch 281 energized to cause the counter to reset to zero forbeginning the next counting sequence. While the clutch is so energizedfor the counter to reset itself to zero, opening and closing of thecounting switch 284 has no effect on the counter. This period of timeis, however, extremely short and less than the time of arrival ofsubsequent or following items from the stacking conveyor so that thecounter is reset for counting between the last item of one stack and thefirst of the next stack. When the predetermined time for which the timedelay relay has been set has expired, the contacts 285 and 290 of therelay are reopened, deenergizing the clutch solenoid 281, and the airvalve solenoid 170a so that the air valve member 17011 of the air valveis returned to its other end position for supplying air to the oppositeends of the air cylinders 160 and 161 extending the pistons to theiropen positions and thus returning the plates 24 and 25 to their stacksupporting closed positions. Simultaneously, the deenergizing of theclutch solenoid releases the clutch allowing the counter to start a newcounting sequence. Thus, the system begins another sequence of countinga predetermined number of the items stacking them and depositing them onthe discharge conveyor.

The counting and stacking system is particularly well suited to thehandling of tortillas, which are a Mexican food product in the form of athin unleavened cake which may be served either in a soft flexible formor a hard brittle toasted form. The counting and stacking apparatus isespecially efiective in packaging the soft flexible form of thetortilla. Tortillas are generally cooked in a conveyortype oven, notshown, in which they are moved on a conveyor spaced one from the otherin a line along a belt type conveyor. The tortillas are moved from theoven on a suitable cooling conveyor which may comprise the conveyor 30 aportion of which is shown in FIGS. 1 and 2. The cooling conveyor allowsthe tortillas to cool to the desired degree and feeds them to thecounting and stacking apparatus 20. The cooling conveyor delivers theline of the tortillas 32 one at a time to the upper end of the conveyorwhere they are discharged downwardly onto the upper end of the slide 33which delivers the tortillas in sequential aligned relationship to thestacking conveyor 84. The wide upper end of the slide permits somemisalignment of the tortillas on the cooling conveyor while the narrowlower end of the slide assures alignment of the tortillas on thestacking conveyor with the stacking guide 22 The line of tortillas isconveyed along the belt of the stacking conveyor to the opposite end ofthe conveyor where each tortilla is launched or projected outwardly anddownwardly from the conveyor into the stacking guide 22 where thetortilla strikes the stacking plate 23 and engages the microswitch lever134 which sets in motion the previously described electrical and aircontrol system for retracting the stacking plate and initiating thedownward air blast from the air head 140. The tortilla momentarily comesto rest on the stacking plate for a sufficiently brief time to orient itat a substantial horizontal position, immediately following which thestacking plate is rapidly retracted from beneath the tortilla and air isblown downwardly from the nozzles 151 to push the tortilla downwardly tothe stack support plates 24 and 25. Partial confinement of air withinthe stacking guide below the dropping tortilla provides a cushioningetfect which eases the tortilla onto the previously stacked oneminimizing damage, wrinkling, and other possible deformations of thetortilla. When the desired number for which the counter has been set hasbeen delivered to and dropped by the stacking plate and arranged instacked form within the stacking guide on the stack support plates, thestack support plates are rapidly retracted to their open positionsallowing the stack of tortillas to drop downwardly to the dischargeconveyor belt 31 which moves the stack in the direction of the arrow 34for further processing such as packing in boxes and the like. Thecomplete sequences of operation of the stacking plate 23 and the stacksupport and discharge plates 24 and 25 are completely repeated for eachstack of tortillas arranged and discharged to the discharge conveyor.If, for example, each stack of tortillas contains twelve tortillas, thestacking plate 23 and the air head operate twelve times for each stack,the plate withdrawing and the air head blowing downwardly each time atortilla is deposited in the stacking guide, while the stack support anddischarge plates 24 and 25 move to their open positions once for eachstack of twelve tortillas as the stack is released to the dischargeconveyor.

The rates of speed of the various conveyors are coordinated with thecontrol system of the apparatus so that the process beginning with thesupply of tortillas on the cooling conveyor through the removal of thestacks by the discharge conveyor proceeds in a systematic time sequencewithout the overlapping of stacks and other related problems. Thecounter 273 may, of course, be adjusted within certain limits to providestacks of any desired number within the structural limitations of theapparatus which includes such factors as the height of the stack supportplates above the discharge conveyor.

The counting and stacking apparatus has been illustrated and describedin terms of a single unit. Multiple units in side-'by-side relationshipmay be used to process several rows of items disposed in generallyparallel relationship. For example, where a tortilla oven utilizes aconveyor carrying three rows of tortillas the counting and stackingapparatus may provide for simultaneously counting and stacking items ineach of the rows of tortillas as they are delivered by the coolingconveyor to the apparatus. Such 1 1 a multiple application requires aseparate line-up slide and separate assemblies of a stacking plate, astacking guide, and stack support and discharge plates with relatedcontrol systems for each line of tortillas handled. A single stackingconveyor and a single discharge conveyor may, however, be combined withthe stacking and counting apparatus with three rows of tortillasarranged side-byside on the stacking conveyor and three rows of stackedtortillas arranged side-by-side moved away on the discharge conveyor.Also, a single air supply may be used for furnishing air to the threeseparate control systems of the three separate counting and stackingarrangements.

Other modifications within the scope of the invention will be obvious tothose skilled in the art, such, for example, the use of a single stacksupport and discharge plate in lieu of the preferred oppositely movingpair of discharge plates described and illustrated herein. Obviously,such a single plate must be larger, will involve movement of more mass,and would require more rapid movement to properly release a stack to thedischarge conveyor without affecting the horizontal position of thestack as it is dropped.

It will now be seen that a new and improved system for counting andstacking has been described and illustrated. It will also be seen thatthe apparatus is particularly adapted to the handling of substantiallyflat items and especially such items as food products such as tortillasof the soft variety. It will be further seen that the system arranges adesired number of items in stacked aligned relationship and moves eachstack to a location for further processing, such as packing incontainers and the like. It will also be seen that the counting andstacking apparatus includes a stacking conveyor, a stacking plate forlining up and dropping each handled item into stacked relationship belowthe stacking plate, stack support and discharge plates below thestacking plate for holding each stack of items until the stack comprisesthe desired number and then discharging the stack to a dischargeconveyor below the stack support and discharge plates for movement to alocation for a further processing, such as packing in containers. In itspreferred arrangement the counting and stacking apparatus is used with asupply conveyor which in the case of tortilla handling is a coolingconveyor from a cooking oven and a line-up slide for delivering theitems from the supply conveyor to the stacking conveyor of the apparatusso that the items are properly aligned on the stacking conveyor fordeposit on the stacking plate.

The foregoing description of the invention is explanatory only andchanges in the details of the construction illustrated may be made bythose skilled in the art without departing from the spirit of theinvention.

What is claimed and desired to be secured by Letters Patent is:

1. Apparatus for counting and stacking a plurality of substantially flatflexible articles comprising: supply means for feeding said articlesinto said apparatus comprising an endless belt-type conveyor fordepositing said articles one at a time into said apparatus; stackingmeans comprising a substantially horizontal plate rapidly reciprocablealong a straight line in the direction of movement of said endlessbelt-type conveyor to individually receive each of said articles fromthe discharge end of said conveyor, to momentarily support each of saidarticles, and to release each of said articles to drop downwardly to astacked relationship below said plate, said plate being disposedimmediately adjacent to the discharge end Of said endless belt-typeconveyor at a first position for receiving and supporting each of saidarticles individually and being movable away from said discharge end ofsaid conveyor to a second article release position spaced from saiddischarge end of said conveyor and returnable along said line to saidfirst position; stack support and discharge means comprising ahorizontally recip'rocable plate for receiving said articles from saidstacking means, holding said articles in stacked relation-v ship, anddischarging said articles in said stacked relation ship when a desiredpredetermined number of said articles are stacked thereon; a stackingguide disposed between said stacking means and said stack support anddischarge means for engagement by edges of said articles for maintainingsubstantially vertical alignment of said articles and holding saidstacked articles in place on said stack support and discharge means; airmeans supported above said stacking means for discharging an air streamdownwardly against each article on said stacking means as said stackingmeans moves from said first article supporting position to said secondarticle release position; a discharge conveyor for receiving each stackof articles from said stack support and discharge means and moving saidstack toward a location for further processing; and counting meansoperatively associated with said stacking means and said stack supportand discharge means and actuated by movement of said stacking plate forcontrolling the operation of said stacking means and said stack supportand discharge means when a predetermined number of said articles isdeposited on said stack support and discharge means by said stackingmeans.

2. Apparatus for counting and stacking soft tortilla food productscomprising: a sloping line-up slide for receiving randomly positionedtortillas at an upper end thereof from a cooling conveyor anddischarging said tortillas in aligned positions at a lower end thereof;an endless belt-type feeding and stacking conveyor at said lower end ofsaid slide for receiving each tortilla from said slide and moving saidtortilla to and discharging said tortilla from the end of said conveyoropposite said slide; a substantially horizontally positioned rapidlyreciprocable stacking plate movable along the same straight line ofdirection as said feeding and stacking conveyor and closely spaced fromand below the discharge end of said stacking conveyor below the carryingplane surface of said conveyor, said stacking plate being adapted to behorizontally moved from a first tortilla receiving position closelyspaced from said feeding and stacking conveyor where it is normallylocated in a direction away from said conveyor to a second tortillarelease position distantly spaced from said conveyor whereby a tortillamomentarily supported on said stacking plate is released for droppingdownwardly to a stacked relationship below said plate, said stackingplate being adapted to be rapidly retracted from said first position tosaid second position and being surfaced such that the rapid removal ofsaid plate strips a tortilla supported on said plate such that thehorizontal position of said tortilla is unaffected by the withdrawal ofsaid plate whereby said tortilla is dropped in a substantiallyhorizontal position into said stacked relationship below said plate; astack support and discharge plate disposed in a substantially horizontalposition below said stacking plate and adapted to horizontallyreciprocate in the same direction as said stacking plate between a firststack supporting position below said first position of said stackingplate and a second stack discharge position spaced therefrom forreleasing a stack of tortillas supported thereon to permit said stack todrop downwardly therefrom; a stacking guide supported between saidstacking plate and said stack support and discharge plate engageable byedges of said tortillas for holding a stack of tortillas insubstantially vertical aligned stacked relationship on said stacksupport and discharge plate; a discharge conveyor disposed below saidstack .support and discharge plate for receiving each stack of tortillasreleased by said plate and moving said stack away from said apparatustoward a packaging station; switch means associated with said stackingplate including an actuating feeler disposed over said stacking platewithin the line of trajectory of a tortilla propelled from the dischargeend of said feeding and stacking conveyor onto said stacking platewhereby each said tortilla engages said feeler to effect retraction ofsaid stacking plate when said tortilla is supported on the top surfaceof said stacking plate for moving said stacking plate to said secondposition to release said tortilla for dropping downwardly in saidstacking guide to said stack support and discharge plate; and countingmeans responsive to said switch means and adapted to effect retractionof said stack support and discharge plate to said second stack releaseposition when a predetermined number of tortillas are released tostacked position on said stack support and discharge plate by saidstacking plate.

3. A tortilla counting and stacking apparatus as defined in claim 2wherein said stacking plate is provided with a longitudinal slotextending in the direction of movement of said plate and open at one endthrough the edge of said plate toward the discharge end of said feedingand stacking conveyor, and said actuating feeler of said switch means isdisposed through said slot of said stacking plate when said stackingplate is at said first tortilla receiving position closely spaced fromsaid discharge end of said feeding and stacking conveyor whereby saidfeeler is engaged by each tortilla propelled from said feeding andstacking conveyor onto the top surface of said stacking plate.

4. A tortilla counting and stacking apparatus as defined in claim 3wherein said stacking plate has a smooth top supporting surface toprovide maximum stripping action between each tortilla supported on saidplate when said plate is'retracted to said second position.

References Cited UNITED STATES PATENTS 1,563,071 11/ 1925 Brecknell.

2,191,881 2/ 1940 Erikson et a1. 271-88 2,492,024 12/ 1949 McWilliams.

2,697,388 12/ 1954 Hansen et a1.

3,054,516 9/1962 Joa.

3,231,100 1/1966 Faeber.

3,233,891 2/1966 Denton et a1. 271-88 X 3,291,010 12/1966 Williamson.

3,392,853 7/1968 Mitchell et a1.

3,393,645 7/1968 Mason.

3,412,875 11/1968 Weir.

1,826,379 10/1931 Birkmeyer et a1. 19845 X 2,596,228 5/1952 Fletcher19845 X 2,637,450 5/ 1953 Eshelman.

3,3,66,25 3 1/ 1968 Walchhiiter.

GERALD M. FORLENZA, Primary Examiner R. J. SPAR, Assistant Examiner US.Cl. X.R. 19845; 27168

